Use new answer views

The following replacements have been made:
* New design document name
    - New view name: (conditions) keys => values
        * Full old view name: (conditions) keys => values

* answer/
    - by_questionid: questionId => _rev
        * answer/cleanup: questionId => _id
    - by_questionid_piround_text_subject: questionId, piRound, abstention, answerText, answerSubject, successfulFreeTextAnswer => _rev
        * skill_question/count_all_answers_by_question: questionId, answerText, answerSubject, successfulFreeTextAnswer => 1
        * skill_question/count_answers_by_question_and_piround: questionId, piRount, answerText => 1
        * skill_question/count_abstention_answers_by_question: (abstention) questionId => doc
        * skill_question/count_total_answers_by_question: questionId => doc
        * skill_question/count_total_answers_by_question_and_piround: questionId, piRount => 1
    - by_sessionid: sessionId => _rev
        * skill_question/count_answers_by_session: sessionId => doc
    - by_sessionid_variant: sessionId, variant => _rev
        * skill_question/count_answers_by_session_and_question_variant: sessionId, questionVariant => doc
    - by_user_sessionid: user, sessionId => _rev
        * answer/by_user: user, sessionId => questionId
    - doc_by_questionid_timestamp: questionId, timestamp => doc
        * skill_question/freetext_answers_full: questionId, timestamp => doc
    - doc_by_questionid_user_piround: questionId, user, piRound => doc
        * answer/by_question_and_user_and_piround: questionId, user, piRound => doc
    - doc_by_user_sessionid: user, sessionId => doc
        * answer/by_user_and_session_full: user, sessionId => doc
    - questionid_by_user_sessionid_variant: user, sessionId, questionVariant => questionId
        * answer/by_user: user, sessionId => questionId
        * answer/variant_by_user: user, sessionId, questionVariant => questionId
    - questionid_piround_by_user_sessionid_variant: user, sessionId, questionVariant => questionId, piRound
        * answer/variant_by_user_and_piround: user, sessionId, questionVariant => questionId, piRound